With Donald Trump formally chosen as their nominee for president, Republicans at their convention in Cleveland turn Wednesday to some of the party's biggest names in the 2016 campaign to make the case that he is a better choice for the country than Democrat Hillary Clinton.

Indiana Governor Mike Pence gets his chance in the speaking spotlight, less than a week after being announced as Trump's running mate. Former House Speaker Newt Gingrich, who was considered for Vice President, is also speaking Wednesday.

Others who battled Trump for the nomination, including those who sharply criticized his policy proposals and endured his retorts and harassing nicknames, will be giving addresses too. They include: Wisconsin Governor Scott Walker, Florida Senator Marco Rubio and Texas Senator Ted Cruz.

Clinton criticized

Tuesday at the convention showcased the main Republican criticisms of Clinton, portraying her candidacy as a bid to extend what they call the failing policies of President Barack Obama and calling her a liar who put the country in danger with her use of a private email server.

House Speaker Paul Ryan accused Democrats of constantly dividing people and "playing one group against the other."

House Speaker Paul Ryan of Wisconsin addresses the Republican National Convention in Cleveland on July 19, 2016. (AP)

"Here we are, at a time when men and women in both parties so clearly, so undeniably want a big change in direction for America, a clean break from a failed system," Ryan said. "And what does the Democratic Party establishment offer? What is their idea of a clean break? They are offering a third Obama term brought to you by another Clinton."

The Clinton campaign was vocal throughout the night, offering statements and tweets in response to each of the day's major speakers.

"Despite repeatedly attacking Trump's divisive rhetoric and dangerous policies, Speaker Paul Ryan has chosen to put politics over country and wholeheartedly endorse Donald Trump and his candidacy for president," one statement read.

New Jersey Governor Chris Christie, who also competed in the Republican race, used his convention address to give a sort of public prosecution of Clinton, drawing chants of "guilty" from the audience.

"Hillary Clinton cared more about protecting her own secrets than she cared about protecting American secrets," Christie said.

His criticism focused largely on her time as secretary of state during Obama's first term, blaming her for mistakes regarding Libya, Syria, Russia, Iran and Cuba.

"We cannot promote someone to commander in chief who has made the world a more violent and dangerous place."

Clinton responded by pointing to a scandal involving members of Christie's administration in New Jersey who were accused of ordering the partial closure of a bridge in retaliation against a local politician.

"If you think Chris Christie can lecture anyone on ethics, we have a bridge to sell you," she wrote on Twitter.

Clinton will be officially nominated by her party at its convention next week, setting up the November 8 showdown with Trump.

Roll call puts Trump over the hump

A roll call vote of Republican delegates Tuesday gave Trump the 1,237 votes he needed to seal the nomination after months of state-by-state voting.

"I will work hard and never let you down!" Trump tweeted after the vote. He gets his chance to address the convention Thursday on its final day.

His daughter Ivanka will also speak Thursday, just as several other Trump children have done this week.

Donald Trump, Jr., son of Republican Presidential Candidate Donald Trump, speaks during the second day of the Republican National Convention in Cleveland, Tuesday, July 19, 2016.

Donald Jr., Tiffany Trump

Donald Trump Jr. gave a strong speech in support of his father Tuesday highlighting how his approach to the business world would translate to the White House.

"A president who speaks his mind and not just when it behooves him to do so. Who doesn't have to run a focus group or use data analytics to form a simple opinion. Who says what needs to be said and not just what you want to hear. A president who will unleash the greatness in our nation and in all of us," he said.